Growth, yield, n uptake and water use efficiency of carrot (daucus carota l.)‎ plants as influenced by irrigation level and nitrogen fertilization rate

الملخص EN

Field experiments were carried out during winter seasons of 2000/20001 and 2001/2002 at the Experimental Farm of the Faculty of Agric., Al-Azhar Univ., Assiut on clay eyloamy soil to study the effect of irrigation levels and N fertilization rates on growth and yield as well as N uptake and water use efficiency of carrot.

The results indicated that frequent irrigation with 100% replenishment of evaporation losses resulted in highest root yield, total dry matter, leaf area index, and N uptake.

Water use efficiency recorded high value with 75% replenishment of evaporation losses.

Also, the results showed that increasing nitrogen rate up to 120 kg N/fed significantly, increased the dry matter, root yields, water use efficiency and N uptake in all tested treatments.

Apparently nitrogen recovery percent increased with evaporation replenishment up to 100% level and with increasing rate of nitrogen up to 80 kg N/fed, then decreased with increasing rate of applied nitrogen.

There were two phases the interaction effect.

First response of root yield to nitrogen increment was significant, at 75% level of evaporation replenishment.

This indicate that evaporation replenishment improved nitrogen utilization.

Secondly, that the response to irrigation level application was, particularly noticed when levels of nitrogen were applied.

The highest root yields were obtained with at 100% evaporation replenishment and 120 kg N/fed.

On the other hand, maximum water use value were recorded with 120 kg N/fed and at 75% level of evaporation replenishment.